Technical Field
Embodiments of the subject matter disclosed herein relate to an engine system.
Discussion of Art
In light of its favorable energy content, natural gas may be used as a fuel source for an engine. However, many existing engines are typically configured with only a single, liquid (e.g., diesel) fuel supply, limiting the opportunities for operating engines with natural gas. When engines are configured to operate with both liquid and gaseous fuel, a trade-off may be made between an optimal compression ratio for liquid versus gaseous fuel operation. For example, a high compression ratio may be preferred for liquid fuel engines in order to provide reliable starting, low power ignition, and high efficiency. In contrast, a lower compression ratio may be preferred for gaseous fuel engines to prevent pre-ignition and allow a high percentage of gaseous fuel substitution at high power levels.